Mechanically operated smelting hearth



Sept. 14, 1937. w. E. NEWNAM MECHANICALLY OPERATED SMELTING HEARTH 2 Sheets-Sheet 1 F QMN m NNN Sept. 14, 1937. w. E. NEWNAM MECHANICALLY OPERATED SMELTING HEARTH Filed June 4, 1928 2 Sheets-Sheet 2 Patented Sept. 14, 1937 UNITED STATES MECHANICALLY OPERATED SMELTING HEART-H William. E. N ewnam,

13 Claims.

This invention relates to smelting hearths, and more particularly to the type described in Patents No. 1,202,408, October 24, 1916; No. 1,263,695, April 23, 1918; andNo. 1,388,144, August 16, 1921.

An ore hearthv designed more particularly for the smelting of lead, comprises, a comparatively deep basin of cast iron, a water back having twyers at the lower end thereof positioned just above the basin, an apron which extends forwardly from the basin and a hood which extends over the hearth. In the operation of such a hearth, the basin is filled nearly full of lead, which is brought to a molten condition and the ore and fuel are then placed so as to float, on

' top of this bed of molten metal in the basin,

and banked up against the water back. If a blast is now applied to the twyers a part of the ore is reduced to a molten state and settles in the basin while the unmolten clinker rises to the top. In the operation of such a hearth, more particularly of the character described in the above patents, the charge of ore and fuel banked against the water back is rabbled so as to turn over and work up the material on the hearth and bring the grey clinkerto the surface; this rabbling proceeds from one end to the other of the hearth, and is succeeded by a backing operation which pushes back the rabbled charge against the water back. The clinker is picked off and removed from the hearth for subsequent reduction on a blast furnace. Small quantities of ore and fuel in a ground condition are scattered over the hearth after the chargehas been rabbled and pushed back. The operations of. rabbling, pushing back the rabbled charge, and distribution of fuel are then again proceeded with. The molten metal will overflow and discharge into molds to form pig lead; and grey clinker is extracted for smelting and the fumes given off during the smelting operation pass upwardly and are caught by the hood whence they pass to the baghouse where they are collected, sintered and smelted.

The length of a hearth of the type described in the above patents is limited from a metallurgical standpoint, for a long continuous structure is not sufficiently elastic to permit right control of the temperature, exhaust, rabbling, backing and addition of fuel. Accordingly, the length of the hearth should be proportioned to correspond to the movement of the rabbling and backing devices, and to the period of smelting of the ore added to the hearth. As a practical proportion, therefore, a hearth eight feet in length is found to secure the best results.

Collinsville, Il1., assignor to National Lead Company, St. Louis, Mo., acorporation of New Jersey Application June 4, 1928, Serial No. 282,664

PATENT OFFICE In Patent. No. 1,263,695, rabbling and backing devices are arranged in cooperative relation on' a carriage moving along the hearth so as. to suecessively rabble the charge and push back the rabbled. charge against the apron; the backing 5 device being arranged. alongside of the rabbling device. It isdesirable, however, that. the charge on the hearthbe completely rabbled as. well as pushed back from one end of the hearth to the other, for otherwise the material near the ends. .10

of the hearth may not receive proper treatment, thereby resulting in. loss of efiiciency. In a hearth of this type, however, and of limited length, as shown and described in Patent No. 1,388,144, the. water back extends forwardly at the endsto provide. water jackets at the ends of the hearth- If the backing device is arranged. alongside of the rabbling device, so as to follow the same fromone end of the hearth to the other, the water back end will interfere with. the operation of the backing device, unless the carriage is stopped when the backing device reaches the end; this, however, prevents eflicient rabbling of the material charge near that end.

One of the objects. of this: invention, therefore, is to provide a smelting hearth of the character referred to, whereby the charge of material on the hearth may be rabbled from end to end while still permitting the rabbled charge to be pushed back.

Another object is to provide a smelting hearth having a rabbling device as well as a backing device, operating mechanically and adapted to rabble as well as. push back the rabbled charge from end to end of the hearth and without interference with the hearth.

Another object is to provide a hearth of the character described having a backing device which is simple in construction, effective in its action andeconomical to manufacture.

Further objects will appear from the detail description in which Figure 1 is a front elevation of a hearth embodying this invention; and

Figure 2 is an end view.

In accordance with one embodiment of this invention the operation of the backing device is controlled so that this backing device remains inactive and even retarded until after the rabbling device has started. This is accomplished in the particular embodiment disclosed by operating the backing device by a separate train of mechanism controlled by a clutch which does not throw the backing device into operation until 55 after the carriage has moved a predetermined a latch this chain passing over an idler I21.

distance along the hearth. In this way the rabbling device can start at the extreme end of the hearth close up to the forward extension of the water back while the backing device does not come into operation until it passes that forward extension. Means are also provided whereby the operation of the backing device can be at any time interrupted so as to permit pushing back of the rabbled charge by hand and independent of the operation of the backing device. A yields ing connection is provided between the backing device and its operating mechanism so, that the backing device is protected from damage should it strike an obstruction.

Referring now to the accompanying drawings, the hearth I is shown as provided with a basin 2, an apron 3 and a water back 4 having forward extensions 430, tWyers 5 and a hood I0. Standards 23, carry-rails 2| supporting a carriage 22 having wheels 23 and 24 running on the rails whereby the carriage is suspended for movement along the hearth. The wheels 23 are fixed to a shaft 25 having a ratchet 26 engaged by a pawl 27 moving over a shield 82, this pawl being actuated by a link from an eccentric 36 on the shaft 38. This shaft has a gear 39 arranged to be clutched thereto by a clutch 933, and this gear is driven from the motor 45 through a train of gears 45, 43, and 44. The shield 82 is connected with a rock shaft 85 which has an arm I33 provided with a cam roll engaging a cam I95. on one of the rails 2|. The rock shaft 86 is further connected by a link 88 with an arm 33 controlling the clutch 933, which is held by I03. A chainfiIi connects a sprocket attached to the gear 39 with a sprocket on a shaft 63 connected by bevelled gears with a shaft I3 fixed to the wheels 24; a clutch 59 connects the sprocket with the shaft 58 and is controlled by an operating device 80. A crank disk 55 fixed to the shaft 38 has a crank pin 51 through which passes a rabbling device supported by a fork 60 on the carriage 22.

The parts so far described are substantially as shown and described in Patent No. 1,388,144, to whichreference is had for details. Assuming the carriage to be in the position shown in Figure 1, the operator throws the clutch 39 by pulling on 33 thereby causing the carriage to move to the left, the clutch being disengaged, when the rabbling device .55 reaches the end 433 of the water back, by the lug 8I; during this return movement the rabbling device is retracted. The operator will then disengage the latch I03 thereby engaging the clutch 93D and shifting the shield 82 to permit the pawl 2'I to operate on the ratchet 26. The carriage will now be fed step by step to the right Figure 1 while the rabbling device is operated to rabble the charge on the hearth, the rabbling device being retracted while the carriage is being fed a step. When the rabbling device reaches the other end of the hearth the arm I63 strikes the cam I35 to again shift the shield 82 and disengage the clutch 930.

Attached to the side of the carriage 22 is a carriage I22 for the backing device. Extending along the carriage 22I22 is a shaft I23 having loose thereon a sprocket I24 connected by a chain 525 with a sprocket I25 on the shaft 38, A clutch 5.28 splined on the shaft I23 is normally held by a spring I29 into engagement. A clutch actuator I35 pivoted on the carriage has a cam roll I3I arranged to ride on a cam I32 on one of the rails 2I when the backing device reaches the forward extension 403 of the water back. The shaft I23 drives a shaft I 33 through bevel gears I34 while the shaft I33 in turn drives a shaft I35 through bevel gears I36.

The shaft I23 has fixed thereto a crank disk I3'I having a crank pin I38 between the forks of which is pivoted a guide I39 to slidingly engage the end I 40 of the lever pivoted at |4I on the carriage I22. The other end I42 of this lever has pivoted thereon at I43, the backing device carrier I44 which is pivoted at I45 to a link I46 which has pivoted thereto a slide I4! moving in a guide I48 on the carriage I22. The link I46 is forked as shown at I49 to embrace a cam I50 on the shaft I35 which cam is engaged by a cam roll I5I on the slide M1. The backing device proper has a head I52 whose shank I53 slides in the carrier I44 while interposed between the two is a spring I54. This spring bears against a key I55 attached to the shank I53 and moving in a closed slot in the carrier I44 so as to limit the forward movement of the rabbling device while providing a yielding connection.

Assuming that the carriage 22I22 is moved to the left, before the rabbling device reaches the left forward extension 400 of the water back, the cam roll I3I will ride on the cam I32 in order to disengage the clutch I28 while the carriage is permitted to move on until the rabbling device is near that extension. When now the latch I30 is disengaged the carriage will move step by step to the right while the rabbling device operates to rabble the charge on the hearth. As soon as the backing device clears the extension 400 the roll I3I will drop off of the cam I32 so as to throw the backing device into operation. It will be noted however, that the clutch I28 is a single tooth jaw clutch so as to come into action in one position of the clutch which is driven directly from the same shaft 38 that the rabbling device is driven from. When the backing device, therefore, starts into operation it will start in step with the rabbling device and the transmitting mechanism is so constructed that the backing device follows closely upon the rabbling device; in other words, the backing device moves forward shortly after the rabbling device moves forward. This backing device moves in the path shown in dotted lines in Figure 2, so as to move along the apron and in inclined upward direction in order to push the material against the water back, while the return path is higher so as to clear the bed of material. When the carriage 22-I22 reaches the right hand position the clutch 930 is again disengaged while the shield 82 is again shifted to a position to stop the feeding. The cycle can then be repeated.

It will, therefore, be seen that the invention accomplishes its objects. By means of the mechanism described the rabbling as Well as the backing of the charge can be performed in an efficient manner. As the rabbling device moves into and out of the material the grey slagiis brought to the surface. The backing device follows closely upon the rabbler and immediately thereafter so as to cover up the charge. the surface will be pushed up towards the water back, but as the backing device returns this slag will roll back upon the apron where it can be removed by the operator. The operator will follow up the backing device picking out the slag and distributing additional ore and fuel over thehearth. Due to the control of the backing device the rabbling can be carried out thefull length Any slag brought to ing device mounted plated by and is Within the scope of the appended claims. It is, further, obvious that various changes may details of construction shown and/ or described.

Having thus described the invention what is claimed is:

1'. A smelting furnace comprising, a hearth adapted to receive molten metal upon which be smelted, mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted to push back the rabbled charge, means for opoperative relation, and means controlling the operation of said backing device independently of said rabbling device.

2. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted to push back the rabbled charge, means for operating said rabbling and backing devices in cooperative relation, and means for starting theoperation of said backing device after said rabbling device has started.

3. A smelting furnace comprising, a hearth adapted to receive molten metal upon which. floats the material to be smelted, a carriage: mounted for movement along said hearth, a rabbling device mounted on said carriage and adapt-- ed to rabble the charge on said hearth, a back-- on said carriage and adapted to push back the rabbled charge, means for operating said rabbling and backing devices in cooperative relation, and means for interrupting the operation of said backing device while said rabbling device remains in operation.

4. A smelting furnace, comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a rah-- bling device mounted on said carriage and adapt--- ed to rabble the charge on said hearth, a backing device mounted on said carriage and adapted topush back the rabbled charge, separate mecha nisms for operating said rabbling and backing devices in cooperative relation, and means for stopping the operation of said backing device operating mechanism independently of the rabbling device.

5. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted to push back the rabbled charge, meansfor feeding said carriage along said hearth, means for operating said backing and rabbling devices in cooperative relation and with said feeding means, and means for starting the operation of said backing means after said carriage has started.

6. A smelting furnace comprising, a hearth adapted to receive molten =1netal upon which floats the material tobe smelted, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted to push back the rabbled charge, means for feeding said carriage along said hearth, means for operating said backing and rabbling devices in cooperative relation and with said feeding means, means for starting the operation of said carriage feeding means and said rabbling device, and means operating to thereafter startthe operation of said backing means.

7. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted to push back the rabbled charge, means for imparting a step by step feeding movement to said carriage, means for operating said backing and rabbling devices in cooperative relation and with said feeding means, and means for starting the operation of said backing device after said carriage has started.

8. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted. to push back the rabbled charge, means for imparting a step by step feeding movement to said carriage, means for operating said backing and rabbling devices in cooperative relation and with said feeding means, means for starting the operation of said backing device after said carriage has started, and means for returning said carriage while the operation of said rabbling and backing devices are stopped.

9. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted to push back the rabbled charge, means for feeding said carriage along said hearth, means for operating said backing and rabbling devices in cooperative relation and with said feeding means, and means for interrupting the operation of said backing device while said rabbling device and said feeding means continue in operation.

10. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted to push back the rabbled charge, means for feeding said carriage along said hearth, means for operating said backing and rabbling devices in cooperative relation and'with said feeding means, and means for suspending the operation of said backing device while said carriage moves a predetermined distance with said rabbling device in operation.

11. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage and adapted to push back the rabbled charge, means for feeding said carriage along said hearth, means for operating said backing and rabbling devices in cooperative relation and with said feeding means, and means for holding said backing device retracted while said carriage moves a predetermined distance with said rabbling device in operation.

12. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a carriage mounted for movement along said hearth, a backing device mounted on said carriage and adapted to push back the charge on said hearth, means for operating said backing device and for feeding said carriage in cooperative relation, and means for starting the operation of said backing device after said carriage has started.

13. A smelting furnace comprising, a hearth adapted to receive molten metal upon which floats the material to be smelted, a water back extending forwardly at the end of said hearth, a carriage mounted for movement along said hearth, a rabbling device mounted on said carriage and adapted to rabble the charge on said hearth, a backing device mounted on said carriage alongside of said rabbling device and adapted to follow said rabbling device to push back the rabbled charge, and means for operating said rabbling and backing devices in cooperative relation to rabble the charge on said hearth from end toend without interfering with the ends of said water back.

WILLIAM E. NEWNAM. 

